that for the entirety of the law enforcement should be combhited to their efforts. >> court documents contain new details about thursday night's carjacking. the fbi show tamerlan and dzhokhar tsarnaev in cambridge at a gas station where they drove with the owner of the suv they carjacked. one began the carjacking by pointing a gun at the driver and saying, "did you hear about the boston explosion? i did get" the carjacker showed the driver he had bullets in his gun according to fbi and said, "i'm serious." at the shooting in watertown where tamerlan was killed, other explosives were found. a boston police commissioner says that's one reason he thinks the brothers planned other attacks. >> we got to step over some unexploded devices that they threw at the officers and i can only understand from that that they had other targets. they were going other places. >> that's nbc news' pete williams reporting. >>> well, today members of the house will get a top secret briefing on the boston bombings. meanwhile, the head of the senate intelligence committee is demanding the fbi explain why more